High resolution pressure sensing

ABSTRACT

A pressure sensing device that may include a first and second sensing elements that comprise one or more piezoresistive materials; wherein the first sensing element has a first gradient; wherein the second sensing element has a second gradient; wherein the second gradient differs from the first gradient; wherein the first and second gradients facilitate a determination of a load of and a location of an event that involves applying pressure on the first and second sensing element.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims the priority from U.S. provisional patent Ser.No. filing date 62/089,268 filing date Dec. 9, 2014 which isincorporated herein in its entirety.

BACKGROUND

Smart patches, such as electronic skin (e-skin), are pixelated flexiblesensing array, which senses external and environmental stimuli, in amanner similar to human skin. Smart patches has been produced fromdiverse technologies, such as semiconducting organics, nanowires, carbonnanotubes, and nanofibres.

Although promising results have been achieved with these technologies,the multi-pixel integration, complicated wiring, applied voltage, andanalysis remain challenges to overcome. For example, 10×10 pixelatedsmart patch requires 200-300 wiring devices and 100 electricalmeasurement devices, thus increasing the energy consumption and thesmart patch cost.

In general, the electrical resistance of GNP film depends on theinter-particle distance. When a GNP film is deposited on a flexiblesubstrate, deformation of the substrate affects the inter-particledistance in the film and the resistance changes accordingly.

A schematic representation of GNPs on an elastically deformed flexiblesubstrate is depicted in FIG. 1A. However, for smart patchesapplications, many pixels and associated wiring are required. In apixelated array of strain/pressure sensors, the resolution is limited bythe pixel size, and sensitivity differences between pixels might reducethe overall pressure resolution and detection limit.

SUMMARY

According to various embodiments of the invention there may be provideda pressure sensing device and/or a method for activating the pressuresensing device.

According to various embodiments of the invention there may be provideda pressure sensing device that may include a first and second sensingelements that may include one or more piezoresistive materials; whereinthe first sensing element has a first gradient; wherein the secondsensing element has a second gradient; wherein the second gradientdiffers from the first gradient; wherein the first and second gradientsfacilitate a determination of a load of and a location of an event thatinvolves applying pressure on the first and second sensing elements.

The one or more piezoresistive materials may be electrically conductivenanoparticles.

The one or more piezoresistive materials may be nanotubes.

The one or more piezoresistive materials may be nanowires.

The one or more piezoresistive materials may be carbon nanotubes.

The one or more piezoresistive materials may be carbon nanowires.

The pressure sensing device wherein at least one of the first and secondgradients may be a thickness gradient.

The pressure sensing device wherein at least one of the first and secondgradients may be a width gradient.

The pressure sensing device wherein at least one of the first and secondgradients may be a concentration gradient.

The pressure sensing device wherein at least one of the first and secondgradients may be a resistance gradient.

The pressure sensing device wherein at least one of the first and secondgradients may be a sensitivity to strain gradient.

The pressure sensing device wherein at least one of the first and secondgradients may be capping layer thickness gradient.

The pressure sensing device , further may include a sensing circuit thatmay be coupled to the first and second sensing elements, may be arrangedto sense at least one out of resistance and conductance of at the firstand second sensing elements and to determine at least one out of alocation and a load of an event that involves applying pressure on thefirst and second sensing elements.

The first sensing element may include multiple first regions, whereinthe multiple first regions differ from each other by location; whereinat an absence of the event there may be a one to one mapping between agiven property of a first region and a location of the first region.

The second sensing element may include multiple second regions, whereinthe multiple second regions differ from each other by location; whereinat an absence of the event there may be a one to one mapping between agive property of a second region and a location of the second region.

The one to one mapping between the given property of the first regionand the location of the first region may be anti-symmetric to the one toone mapping between the given property of the second region and thelocation of the second region.

The first gradient may be anti-symmetric to the second gradient.

The sensing circuit may be arranged to determine the location at aspatial resolution that may be a fraction of length of first sensingelement.

The sensing circuit may be arranged to determine the location at aspatial resolution that may be less than one percent of the length ofthe first sensing element.

According to various embodiments of the invention there may be provideda pressure sensing device that may include a sensing element array thatmay include multiple sensing elements that may include one or morepiezoresistive materials; wherein the sensing element array may becharacterized by a sensing array given property function that mapsvalues of a given property of the multiple sensing elements to at leastone out of location and a load of an event that involves applyingpressure on at least one sensing elements of the sensing element array;wherein the location of the event may be selected out of a group oflocations that may be associated with the sensing element array; andwherein each one of the multiple sensing elements may be associated witha plurality of location of the group of locations.

The given property may be resistance.

The given property may be sensitivity.

The one or more piezoresistive materials may be electrically conductivenanoparticles.

The one or more piezoresistive materials may be nanotubes.

The one or more piezoresistive materials may be nanowires.

The one or more piezoresistive materials may be carbon nanotubes.

The one or more piezoresistive materials may be carbon nanowires.

The pressure sensing device may include a sensing circuit that may becoupled to the sensing element array, may be arranged to senseresistances of at least some of the multiple sensing elements of thearray and to determine the location and the load of the event.

The pressure sensing device 9 wherein at least two of the sensingelements of the sensing element array differ from each other by theirsensing element given property function.

The at least two of the sensing elements of the sensing element havesensing element given property functions that may be anti-symmetrical toeach other.

The pressure sensing device may have a pair of pressure sensing elementsmay be characterized by a given property function that may be injunctiveand maps values of the given property of the sensing elements of thepair to at least one out of location and a load of a deformation eventapplied on at least one of the sensing elements of the pair.

The sensing elements of the pair have sensing element given propertyfunctions that may be anti-symmetrical to each other.

The array of sensing element may be a strip that may include two sensingelements that may be substantially parallel to each other.

The pressure sensing device wherein sensing element array may includefirst and second layers of sensing elements; wherein the first layer ofsensing elements may be positioned above the second layer of sensingelements.

The first and second layers of sensing elements may be substantiallyparallel to each other.

The first and second layers of sensing elements may be substantiallynormal to each other.

The first and second layers of sensing elements may be oriented inrelation to each other.

The pressure sensing device may include an intermediate isolating layerthat may be positioned between the first and second layers.

The pressure sensing device may include at least one intermediate layerthat may be positioned between the first and second layers.

The pressure sensing device may include at least one protective layerthat may be coupled to an exterior facet of at least one of the firstand second layers.

The pressure sensing device wherein each one of the multiple sensingelements may be associated with at least one hundred location of thegroup of locations.

The sensing circuit may be coupled to the sensing element array by a setof conductors, wherein a number of conductors may be in an order of anumber of the multiple sensing elements.

The sensing element array may be flexible.

The pressure sensing device wherein a sensing element of the multiplesensing elements has a spatial character that monotonically changesalong a longitudinal axis of the sensing element.

The spatial character may be a width of the sensing element.

The spatial character may be a height of the sensing element.

The pressure sensing device wherein a sensing element of the multiplesensing elements has an electrically conductive nanoparticlesconcentration character that changes along an axis of the sensingelement.

The pressure sensing device wherein a sensing element of the multiplesensing elements has an electrically conductive nanoparticlesconcentration character that monotonically changes along a longitudinalaxis of the sensing element.

The pressure sensing device wherein a sensing element of the multiplesensing elements has a resistance that monotonically changes along alongitudinal axis of the sensing element when the sensing element may benot under pressure.

The pressure sensing device wherein each sensing element may be a strip.

According to various embodiments of the invention there may be provideda pressure sensing device that may include multiple pairs of sensingelements that may be arranged in a serial manner to cover differentregions of the sensing device; wherein each pair of sensing elements mayinclude a first and second sensing elements that may include one or morepiezoresistive materials; wherein the first sensing element has a firstgradient; wherein the second sensing element has a second gradient;wherein the second gradient differs from the first gradient; wherein thefirst and second thickness gradients facilitate a determination of aload of and a location of an event that involves applying pressure onthe first and second sensing elements.

The multiple pairs of sensing elements may be coupled to conductors thatprovide independent access to each one of the pairs of sensing elements.

The pressure sensing device wherein multiple pairs of sensing elementsmay be coupled to a flexible substrate and may be configured to sensebending points of the flexible substrate.

The different regions may be serially positioned regions.

The different regions may be non-overlapping.

The different regions partially overlap.

According to various embodiments of the invention there may be providedmethods for operating any of the mentioned above pressure sensingdevices and/or methods for manufacturing any of the mentioned abovepressure sensing devices.

According to various embodiments of the invention there may be provideda method for sensing, the method may include providing a pressuresensing device that includes a first and second sensing elements thatcomprise one or more piezoresistive materials; wherein the first sensingelement has a first gradient; wherein the second sensing element has asecond gradient; wherein the second gradient differs from the firstgradient; wherein the first and second gradients facilitate adetermination of a load of and a location of an event that involvesapplying pressure on the first and second sensing elements; and sensing,by the pressure sensing device, the load and the location of the event.

According to various embodiments of the invention there may be provideda method for sensing, the method may include providing a pressuresensing device that includes a sensing element array that comprisesmultiple sensing elements that comprise one or more piezoresistivematerials; wherein the sensing element array is characterized by asensing array given property function that maps values of a givenproperty of the multiple sensing elements to a location and/or a load ofan event that involves applying pressure on at least one sensingelements of the sensing element array; wherein the location of the eventis selected out of a group of locations that are associated with thesensing element array; wherein each one of the multiple sensing elementsis associated with a plurality of location of the group of locations;and sensing, by the pressure sensing device, the load and the locationof the event.

According to various embodiments of the invention there may be provideda method for sensing, the method may include providing a pressuresensing device that includes multiple pairs of sensing elements that arearranged in a serial manner to cover different regions of the sensingdevice; wherein each pair of sensing elements comprises a first andsecond sensing elements that comprise one or more piezoresistivematerials; wherein the first sensing element has a first gradient;wherein the second sensing element has a second gradient; wherein thesecond gradient differs from the first gradient; wherein the first andsecond thickness gradients facilitate a determination of a load of and alocation of an event that involves applying pressure on the first andsecond sensing elements; and sensing, by the pressure sensing device,the load and the location of the event.

BRIEF DESCRIPTION OF THE DRAWINGS

The subject matter regarded as the invention is particularly pointed outand distinctly claimed in the concluding portion of the specification.The invention, however, both as to organization and method of operation,together with objects, features, and advantages thereof, may best beunderstood by reference to the following detailed description when readwith the accompanying drawings in which:

FIG. 1A illustrates a strip according to an embodiment of the invention;

FIG. 1B illustrates a strip according to an embodiment of the invention;

FIG. 2 illustrates a strip and a testing element that scans strip andapplies pressure at different positions during a calibration stageaccording to an embodiment of the invention;

FIG. 3 illustrates a correlation coefficient between the predicted andthe actual load according to an embodiment of the invention;

FIG. 4 illustrates the predicted and the actual position according to anembodiment of the invention;

FIG. 5 illustrates a response of the strip to continuous deformationevents of loads in the range 0.02-1.5 gr at different location,according to an embodiment of the invention;

FIG. 6 illustrates a mathematical model for predicting the location andthe load in the strip of FIG. 1A according to an embodiment of theinvention;

FIG. 7 illustrates a patch that includes a strip and a finger accordingto an embodiment of the invention;

FIG. 8 illustrates a strip that include a dual layer array according toan embodiment of the invention;

FIG. 9 illustrates resulting prediction of loads and positions of thestrip of

FIG. 8 according to an embodiment of the invention;

FIG. 10 illustrates a finger that contacts the strip of FIG. 8 and apressure that is applied at a certain location according to anembodiment of the invention;

FIG. 11 illustrates a rectangular double-layered sensing element arrayaccording to an embodiment of the invention;

FIG. 12 illustrates a relationship between dimensions and number orcomplexity of wiring and/or of readout circuits according to anembodiment of the invention;

FIG. 13 illustrate experimental results according to an embodiment ofthe invention;

FIG. 14 illustrates a method according to an embodiment of theinvention;

FIG. 15 illustrates a method according to an embodiment of theinvention;

FIG. 16 is an image of a setup in which the contacts were printed usingcommercial silver ink and the sensing layer was printed using a custommade gold nanoparticles ink according to an embodiment of the invention;

FIG. 17 illustrates a multi-bending monitoring strip (MBMS) according toan embodiment of the invention;

FIG. 18 illustrates a ring shaped sensing element according to anembodiment of the invention;

FIG. 19 illustrates a printed hexanethiol capped NP with width gradientaccording to an embodiment of the invention;

FIG. 20 illustrates a sensitivity of a width gradient sensor to constantspeed strain as a function of the location along the sensing stripaccording to an embodiment of the invention; and

FIG. 21 illustrates two layers of a two dimensional array in which thegradient is a width gradient according to an embodiment of theinvention.

DETAILED DESCRIPTION OF THE DRAWINGS

In the following detailed description, numerous specific details are setforth in order to provide a thorough understanding of the invention.However, it will be understood by those skilled in the art that thepresent invention may be practiced without these specific details. Inother instances, well-known methods, procedures, and components have notbeen described in detail so as not to obscure the present invention.

The subject matter regarded as the invention is particularly pointed outand distinctly claimed in the concluding portion of the specification.The invention, however, both as to organization and method of operation,together with objects, features, and advantages thereof, may best beunderstood by reference to the following detailed description when readwith the accompanying drawings.

It will be appreciated that for simplicity and clarity of illustration,elements shown in the figures have not necessarily been drawn to scale.For example, the dimensions of some of the elements may be exaggeratedrelative to other elements for clarity. Further, where consideredappropriate, reference numerals may be repeated among the figures toindicate corresponding or analogous elements.

Because the illustrated embodiments of the present invention may for themost part, be implemented using electronic components and circuits knownto those skilled in the art, details will not be explained in anygreater extent than that considered necessary as illustrated above, forthe understanding and appreciation of the underlying concepts of thepresent invention and in order not to obfuscate or distract from theteachings of the present invention.

Any reference in the specification to a method should be applied mutatismutandis to a device capable of executing the method.

Any reference in the specification to a device should be applied mutatismutandis to a method that may be executed by the device.

According to an embodiment of the invention there is provided a devicethat has sensing elements and has a spatial resolution that is muchfiner than the number of sensing elements. In other words, each sensingelement may represent multiple possible locations—and may be equivalentto multiple pixels. This property of the device is terms“un-pixelated”—as the device does not allocate an entire sensing elementper single location—per pixel.

According to an embodiment of the invention there is provided a pressuresensing device that includes (a) a first sensing element that is made ofor includes one or more piezoresistive materials and has a firstgradient and (b) a second sensing element that is made of or includesone or more piezoresistive materials and has a second gradient thatdiffers from the first gradient. A piezoresistive material may changesits resistivity as a response to pressure or strain e.g.

Non-limiting examples of a piezoresistive materials included in thefirst and/or second sensing elements include nanoparticles, carbonnanotubes and nanowires. In a different embodiment the first and/orsecond elements may include conductive or semi-conductive polymers.

For brevity of explanation the following explanation refers tonanoparticles. Any reference to a nanoparticle should be applied mutatismutandis to a reference to a piezoresistive material such as but notlimited to carbon nanotubes or nanowire.

Non-limiting example of a gradient may include a thickness gradient, awidth gradient, a concentration gradient, a resistance gradient, asensitivity to strain gradient, a capping layer thickness gradient, across section gradient, and the like.

For brevity of explanation the following explanation refers to athickness gradient. Any reference to a thickness gradient should beapplied mutatis mutandis to a reference to any other gradient such asbut not limited to a width gradient, a concentration gradient, aresistance gradient, a sensitivity to strain gradient, a capping layerthickness gradient, a cross section gradient, and the like.

According to an embodiment of the invention there may be provided ananoparticle pressure sensing device, that may include a first sensingelement that comprises multiple electrically conductive nanoparticles;wherein the first sensing element has a first thickness gradient; asecond sensing element that comprises multiple electrically conductivenanoparticles; wherein the second sensing element has a second thicknessgradient that differs from the first thickness gradient. Wherein thefirst and second sensing elements have resistances that once read by asensing circuit allows the sensing circuit to determine a locationand/or a load of an event that involves applying pressure on the firstand second sensing elements. The nanoparticle pressure sensing devicemay include the sensing circuit. Non-limiting examples of first andsecond sensing elements are gold nanoparticles.

According to an embodiment of the invention there may be provided ananoparticle pressure sensing device that may include a sensing elementarray that comprises multiple sensing elements; wherein each sensingelement comprises multiple electrically conductive nanoparticles;wherein the sensing element array is characterized by a sensing arrayresistance function that maps resistances of the multiple sensingelements to a location and/or a load of an event that involves applyingpressure on at least one sensing elements of the sensing element array.The sensing element array may be one dimensional, two dimensional, maybe flexible, shaped as a strip and the like. The sensing element arraymay include one or more layers of sensing elements. The sensing elementarray may be a sensing circuit that is coupled to the sensing elementarray, is arranged to sense resistances of at least some of the multiplesensing elements of the array and to determine the location and the loadof the event. The location of the event is selected out of a group oflocations that are associated with the sensing element array. Each oneof the multiple sensing elements is associated with a plurality oflocation of the group of locations.

According to an embodiment of the invention there is provided a flexiblesubstrate with two parallel gold nanoparticle (GNP) strips withanti-parallel sensitivity gradients for an un-pixelated skin strip thatdiminishes the readout data for two resistance measurements only,acquired through three terminals. The smart patch exhibits highlysensitive prediction of both the load applied and position along thesensing strip and is sensitive to various environmental stimuli, such astemperature, humidity and volatile organic compounds.

The following text assumes that the sensing device include one ormultiple pairs of sensing elements such as GNP sensing strips GSS thatare parallel to each other with opposite thickness gradients. This ismerely a non-limiting example.

According to an embodiment of the invention there is provided a flexiblepolymer foil with two GNP sensing strips (2-GSS) parallel to each otherwith opposite thickness gradients.

A thickness of the sensing element may be measured along any imaginaryaxes that is oriented (for example—normal) to a longitudinal axes of thesensing element. The thickness may, for example, represent the height ofthe sensing element, the width of the sensing element of a combinationof both. Changes in the thickness of the sensing element along itslongitudinal axis may represent changes in the cross section of thesensing element.

FIG. 1A illustrates a strip 10 that includes two GSSs 11 and 12 that arespaced apart from each other and mounted on a flexible substrate 30according to an embodiment of the invention. Both GSSs have a triangularshape with opposite slopes—wherein in one GSS the rightmost edge is of amaximal height and in another GSS the leftmost edge of maximal height.It is noted that the cross section of the GSS may change at anothermanner (for example the width of the GSS can change in an anti-symmetricmanner—as illustrated in FIG. 1B, and/or a combination of both heightand width may change). FIG. 1B also shows conductors 50 and sensingcircuit 70. Sensing circuit 70 measures the resistance of the first andsecond GSSs 11 and 12. It is noted that the number of conductors 50 mayequal four or may differ from four. For example one conductor may beconnected in parallel to one end of each one of GSSs 11 and 12. It isnoted that sensing the resistance is equivalent to sensing theconductivity of the GSSs or any sensing of any electrical and/ormagnetic parameter of the sensing element that is indicative of theoccurrence of the event.

FIG. 2 illustrates a strip 10 that includes two GSSs 11 and 12,conductors 50 and a testing element 40 that scans the two GSS andapplies pressure at different positions during a calibration stageaccording to an embodiment of the invention. The GSS extend over adistance of 8 mm and are spaced apart from each other by 0.5 mm. FIG. 2also illustrates a scanning electron microscope image 60 of one of theGSSs with a scale bar of 50 nanometer.

Due to the gradual changes in the thickness, the electrical property(resistance or conductivity) of GSSs 11 and 12 changes along thelongitudinal dimension in the opposite direction of the neighboringstrip. Consequently, measuring the resistances of the adjacent stripssubjected to load at a specific location enables accurate calculation ofboth the applied load and its location along the sensing strip 10.

It is noted that the strip may include or be coupled to a sensingcircuit such as sensing circuit 70 of FIG. 1B. The sensing circuit 70may be configured to measure the resistance by any known method. Thesensing circuit 70 may be located in proximity to the GSSs, or locatedin a greater distance. It may be a part of a flexible patch or coupledto the patch.

The GSSs may be produced by any applicable method. For example they maybe manufactured by a “propelled anti-pinning ink droplet (PAPID)”manufacturing process which is suitable for fabrication of centimeterslong GNP lines.

Using the PAPID approach, two 8 mm long GNP sensing strips (2-GSS) withcounter-directional thickness gradients and resistance of ˜50 MΩ werefabricated over a strip of polyimide foil. The cross-sectional thicknessgradients and related morphology were studied and verified using HighResolution Scanning Electron Microscopy.

Generally speaking, the average thickness of the “thick” edge segment ofthe strip, middle segment, and the “thin” edge segment of the GSS isabout 4 microns, 1.5 microns and 0.5 microns respectively. Differentaverage thicknesses along the sensing strip of the “thick”, middle and“thin” segments can also be smaller, such as 300 nm, 200 nm and 100 nm.

The GSSs provide a continuous (or defect-free) coverage of the GNPs overthe GSS strip. The GSS may operate in room temperature which isadvantageous for flexible and printed electronics. The GSSs, conductorsand the substrate may be manufactured using a simple fabrication processin which both the conductive electrodes and the sensing strip arefabricated using the same GNP solution and a similar fabricationprocess.

The inventors measured the resistances of the 2-GSS (about 10 times persecond) while constant speed deformation was applied at differentlocations. The predicted load was calculated based on the predefinedcalibration equations set.

The correlation coefficient between the predicted and the actual loadwas calculated for eight (spaced at 1 mm) locations along the 2-GSS. Theresults disclosed high correlations (above 0.99) for all locations, aspresented in graphs 100 of FIG. 3.

The inset 110 of FIG. 3 represents a typical graph of the predicted loadvs. the actual load. In this setup, load variations as small as 0.014 grwere detectable. This load is comparable to the smallest detectableloads reported when using a single pixel.

The same set of equations was used to predict the location on which theload/strain was applied, based on the predicted loads. The predicted vs.the actual position are presented by graph 120 of FIG. 4. The circlesstand for the calculated results and the black line stand for perfectcorrelation.

The inset 130 of FIG. 4 is an example of the predicted position for allloads. The calculated position resolution for the 2-GSS (along thethickness gradient direction) is <1 mm, which is one of the highestlocation resolution yet reported for a pressure sensitive array ofsensors.

For the presented un-pixelated smart patch, the final dimension of thedevice are not affected by dense wiring as might be the case forpixelated technologies and might set back large scale applications.

The GSS can be compared to a series of electrical resistors where theoverall resistance equals the sum of resistances of the local resistors.Therefore, a deformation event at a given location causes a resistancechange that has different characteristics than a deformation event withthe same strain but at a different location. The response of the GSSdevice over time to continuous deformation events of loads in the range0.02-1.5 gr at different location are presented in graphs 140 and 150 ofFIG. —the upper graph 140 refers to a first GSS 10 and the lower graph150 refers to second GSS 12.

For example, when deforming a high resistance (low thickness) segment ofthe GSS device, like location 1 in graph 150, the change in the overallresistance is dramatic and high response to the deformation is recorded.Combining two GSSs with opposite gradients gives a one dimensionalsensor that can act as an smart patch and sense pressure/strain andlocation based on two predefined calibration equations and only tworesistance measurements as the readout data.

The responses of a single GSS to load at specific locations on thelinear sensor were calculated as the difference between the electricalresistance of the deflected sensor, R, and the electrical resistancewith no deflection applied, Rb, relative to Rb.

The 2-GSS strip was assembled on four PDMS supports. Load was applied onthe strip by a 100 μm thick polyester sheet pressing the strip at aconstant speed (1.5 mm/sec). The range of applied load in this setup was0.02-1.5 gr. At each location (1-8) the load was increased and thendecreased while the resistance of the GSS was recorded.

FIG. 6 illustrates a mathematical model for predicting the location andthe load in the strip 10 and 11 of FIG. 1A.

The model for predicting the load and location of a deformation event ona 2-GSS device is based on two sets of calibration experiments, one foreach GSS.

In the calibration process, the 2-GSS device is subjected to acontinuous deflection at different specified locations (x_(i)) along thedevice while measuring the resulting change in load and resistance ofeach GSS at each location.

From these load and resistance measurements linear fits are adjusted foreach GSS at each specific location x_(i) giving a set of linear fits foreach GSS, as summarized in the table 210—see third and fourth columns.

For example, when applying continuous deflection at a specific location,xi, the change in the resistance of GSS₁, R₁, will be linear. Thesensitivity to load at the specific location is the slope, a₁, whichdefines the change in resistance as a function of load.

The intercept, C, will be the resistance of the GSS when no load isapplied.

Linear fits between the load sensitivity of first and second GSS 11 and12 respectively, and the location, x_(i), will give a set of two newequation: R₁=(A₁x+B₁)P+C R₂=(A₂x+B₂)P+D

Adding to these two equations the resistances of the GSSs when no loadis applied (C and D) gives a set of two calibration equations whichdefines the correlation between the measured resistance of each GSS, R₁and R₂, and both the load applied on the GSS and its location—asillustrated in graph 220.

FIG. 6 also illustrates an appliance of load 230 at a specific locationalong strip 10, according to an embodiment of the invention. Each of thefirst and second GSS 11 and 12 is illustrated by a line with varyinggray-levels 211 and 212. The varying gray-levels represent the variableheight (or width) of each one of GSS 11 and 12 or the local sheetresistance. The two calibration equation set will enable the user tocalculate the location of the applied load and the load by simplymeasuring the resistances of the two GSSs. The estimated location 241 ofthe appliance of the pressure (230) is illustrated by black line 241 ofstrip 240.

FIG. 7 illustrates strip 10 that contacts a finger of a hand 30 of aperson according to an embodiment of the invention. Strip 70 is coupledto sensing circuit 70 via conductors. Sensing circuit 70 maysimultaneously (or in a serial manner) measure the resistance of bothsensing GSSs 11 and 12 and apply a mathematical triangulation algorithmbased on two equations with two variables (load and position), fromwhich both the load applied on the 2-GSS and its position along thestrips can be predicted in an analog manner.

According to an embodiment of the invention the GSSs and/or the stripitself may be protected by a protective layer that may be connected tothe GSSs and/or the strip. The protective layer may be thin enough suchas not to isolate the GSSs and/or the strip from pressure and may beflexible. The protective layer may be connected to the GSSs and/or stripat an external facet (directed to the location from which pressure isexpected to be applied) and/or to an internal facet.

FIG. 8 illustrates a dual layer array 10′ in which a pair of GSSs 11 and12 were placed one above the other with one or more PDMS layers 81 and82 protecting them from physical damage, and positioned between the GSSsaccording to an embodiment of the invention. It is noted that anintermediate layer may be provided between the first and second GSSswhich electrically isolating the layers from each other. Graphs 160 and170 of FIG. 9 illustrates the resulting prediction of loads andpositions according to an embodiment of the invention. Positionresolution remains 1 mm, yet the loads applied in this setup are higher(load range: 4.5 gr-35 gr) since the device's substrate is thicker. Thisload range is suitable for sensing 1 μm diameter tip on a finger, aspresented in FIG. 10. FIG. 10 illustrates a finger 300 that contactsstrip 10′, and a pressure that is applied at a certain location 230according to an embodiment of the invention. GSSs 11 and 12 are coupledvia conductors 50 to a sensing circuit (not shown). In addition, thePDMS protective layers provide improved adhesion between device andskin. Unpixelated smart patch can be implanted in a range of applicationlike surgical robotics and wearable sensor in which many pixels, largeamount of readout data and abundance of wiring might hindertechnological progress. Thus, the technology presented is applicable as3-terminal, one-dimensional electronic skin for accurate location andload/strain sensing.

FIG. 11 illustrates a two dimensional sensing device 300 that include afirst layer 311 of sensing element, a second layer 312 of sensingelements and a combination of conductors and substrate 320 according toan embodiment of the invention. The sensing elements of each layer maybe parallel to each other and oriented (for example—by ninety degrees)in relation to the sensing elements of the other layer. The sensingelements of the layers may be, for example, GSS 11 and/or 12. Thesensing elements of the same layer may have a symmetrical orasymmetrical resistance gradient, they may have the same resistancegradient, or may differ from each other. Alternatively, some sensingelements of the same layer may have the same resistance gradient whilesome other sensing elements of the same layer may have differentresistance gradient.

Graph 180 of FIG. 12 illustrates the relationship between a twodimensional array of pixels or sensing strips (referred to as matrixdimension) and the number or complexity of wiring and/or of readoutcircuits. Insert 190 represents the difference in readout or requiredwiring between a pixilated array of pressure sensors and the equivalentsmart patch without difference.

Experimental Results

Sintering and the consequent enlargement of GNPs affect the sensingproperties of the GSS device. The resistance of GNP film decreases withincreasing sintering time (graph 410), which corresponds to effectiveenlargement of GNPs. For example, the initial GSS resistance was2.7·10⁸Ω, Subsequently decreasing to 9.5·10⁶Ω after 5 min sintering at150° C., and finally reaching a value of 5·10⁴Ω after a total of 22.5min sintering. This decrease in resistance is required to producecentimeter scale GSSs with applicable device resistance (˜5.10⁸Ω).

For smart patch applications, high durability and sensitivity towardsstrain (or pressure) are key factors. Fatigue test of GNP devices werecarried out in our previous reports. Reproducible and reliable responseswere recorded up to 10,000 banding cycles. The sensitivity of GNP-basedsensors to strain stems mainly from the tunneling mechanism betweenneighboring nanoparticles. The mean Gauge Factor (GF) and the standarddeviation are shown in graph 420.

The results can be divided into three sections. In section I, during thefirst 15 min of sintering (at 150° C.), there is a gradual linearincrease in the GF from an initial value of 50 up to 220 after 13 minsintering. Indeed, the GF is expected to increase linearly withincreasing GNP size. In section II, a sudden jump to a higher GF value(˜300) is observed after 18 min sintering accompanied by a dramatic(order of magnitude) increase in the standard deviation. The varyinghigh GF measurements in section II continue as long as the sinteringsteps are small (5 min). This phenomenon can be attributed to theformation of cracks during the bending step rather than to the tunnelingmechanism. Finally, in section III, at long sintering times (>35 min),the GF declines to relatively low values of ˜25. The low GF values arerelated to metallic-like behavior.

For conformation of cracks formation during bending in the secondsection, flat and curved (Radius of curvature ˜10 mm) GSS device after a20 min sintering step at 150° C. was scanned at similar locations usingan AFM (images 430). In both cases, aggregates with diameter range of100-500 nm are visible. Yet, for the image of the curved device, thespacing between those aggregates are larger, supporting the mechanism ofcracks opening as the governing strain sensing mechanism. The study ofmechanism controlling pressure/strain sensing enables the fabrication ofun-pixelated smart patches with high sensitivity due to tunnelingmechanism and avoiding unstable cracks formation.

Graph 440 presents high sensitivity to small pressures (0.0015-0.5 kPa),24% kPa⁻¹, and high detection limit of 15 Pa. In addition the responsesto load are highly linear and the behavior to increasing and decreasingthe load is similar. Higher sensitivities were reported in recent yearswith OFET as the active component. Yet, the reported OFET requires highoperating voltages (>20V), while the device presented here can operatein voltages as low as 0.5V, which makes it suitable for mobile andportable applications. Another prominent advantage of the un-pixelatedapproach is that only two resistance measurements and three terminalsare required for an accurate readout of load and location, while in allother smart patch approaches, wiring and simultaneous measurements ofmany pixels hinder future applications of this technology.

The GNP sintering process was found to be very useful for controllingother inherent sensing capabilities of GNP devices like sensingtemperature, relative humidity (RH) and volatile organic compounds(VOCs). Partial sintering of the GSS device raises a new opportunity ofcontrolling and tuning the sensing abilities. For example, Controllingsensitivity to temperature is a major advantage for strain/pressuresensors as it allows reducing temperature related interferences with thesensing signal.

In conclusion, the front line of today's touch and position sensingtechnology relies on a pixelated array of touch sensors which requires adense wiring network in between the sensing “pixels”. To overcome thislimitation, there is provided a flexible linear strain sensor whichsenses, in real-time, the position and strain (or load) of a deformationevent along the sensor. The flexible polymer substrate may be depositedwith 2-GSS that functions as resistive strain sensitive layers. Theresistance of each GSS measured, using two electrodes printed over thepolymer foil, changes in proportion to the deformation of the polymerfoil. Since the NPs film of each of the 2-GSSs is intentionallydeposited with a thickness gradient along the line(counter-directionalbetween the two sensing strips), the resistance change of each line isalso proportional to the location of the deformation event along theline. In this simple design, the sensor predicts both the load appliedto the 2-GSS and the position of the deformation event along the device,using two load and position calibration equations and two resistancereadouts. In addition, the polymer foil with the sensing films can beadhered to a stretchable substrate, such as PDMS, to support the foiland give it skin-like properties. Future prospects of the technologydescribed include printing an array of GSSs for large area sensing.Greater control over the gradient properties of the GSS due to newprinting and patterning technologies should further increase the loadand location sensitivity and provide an easy-to-make, straightforwardtechnology for smart patch application. Layers with differentorientation of such an array in 2D manner might enable sensing oftextured surfaces or multiple strained locations.

Device fabrication.

Kapton substrates were received from DuPont.

Preliminary to electrodes fabrication, substrates were rinsed withEthanol, Acetone and Isopropyl Alcohol following a UVO cleaning processat 150° C. for 5 min. Gold electrodes were fabricated by the propelledanti-ink droplet (PAPID) deposition approach using an ink of Hexanethiol(HT) encapsulated GNPs (the synthesis procedure of GNPs is detailed inthe SI, Section6) accompanied by sintering for 1 hr at 300° C. Briefly,HT encapsulated GNPs were suspended in 7:3 Toluene:Nonane solutionachieving a concentration of 42 mg (GNPs)/ml(solution). The combinationof these two different solvents enabled to actuate a sessile droplet ofthe ink by tilting the substrate in a controlled manner, to create a GNPtrail. The GNP trail was then sintered producing ultrathin conductiveelectrodes with a resistance on the order of tens of ohms. Electrodesfor point devices were fabricated with 1 mm spacing whereas for GSSdevices 8 mm spacing was employed. The GNPs films of the GSSs werefabricated in a similar way using a sessile droplet of the same HTencapsulated GNPs ink which was actuated perpendicularly on top of thegold electrodes. Sintering of the GSSs was done at 150° C. for varioustime periods.

FIG. 14 illustrates method 500 according to an embodiment of theinvention.

Method 500 may start by stage 510 of sensing the resistances of firstand second sensing elements. The first sensing element may includemultiple electrically conductive nanoparticles and has a first thicknessgradient. The second sensing element may include multiple electricallyconductive nanoparticles. The second sensing element has a secondthickness gradient that differs from the first thickness gradient.

Stage 520 may follow stage 510 and may include determining a locationand/or a load of an event that involves applying pressure on the firstand second sensing elements. Method 500 may be applied mutatis mutandison any of pressure sensing devices mentioned in the specification.

FIG. 15 illustrates method 600 according to an embodiment of theinvention.

Method 600 may start by stage 610 of sensing the resistances of at leastsome of multiple sensing elements of a sensing element array. Thesensing element array may include multiple sensing elements. Eachsensing element may include multiple electrically conductivenanoparticles. The sensing element array may be characterized by asensing array resistance function that maps resistances of the multiplesensing elements to a location and/or a load of an event that involvesapplying pressure on at least one sensing elements of the sensingelement array.

Stage 620 may follow stage 610 and may include determining a locationand/or a load of the event. The location of the event is selected out ofa group of locations that are associated with the sensing element array.Each one of the multiple sensing elements is associated with a pluralityof location of the group of locations. Stage 610 may include determiningand/or outputting only one of the load and the location of the event.

The pressure sensing device may be fully printed using conventionalprinting methods (e.g., inkjet printing, pad printing) by which both theconductive layer and the sensing layer are printed on a flexiblesubstrate.

Method 600 may be applied mutatis mutandis on any of pressure sensingdevices mentioned in the specification.

FIG. 16 is an image of a setup 760 in which the contacts were printedusing commercial silver ink and the sensing layer was printed using acustom made gold nanoparticles ink (with hexanethiol as the cappinglayer of the NPs) according to an embodiment of the invention.

FIG. 17 illustrates a multi-bending monitoring strip (MBMS)770 accordingto an embodiment of the invention.

FIG. 17 illustrates four pairs of anti-parallel sensing strips 771, 772,773 and 774 that are arranged in a serial manner—each pair ofanti-parallel sensing strips “covers” a different segment of the MBMSalong a longitudinal axis of the MBMS. Each pair of anti-parallelsensing strips is configured to provide its readings independently (viaconductors 775) of other pairs of anti-parallel sensing strips.

There may be a slight overlap between the pairs of anti-parallel sensingstrips. Alternatively—there may be no overlap between the differentpairs of anti-parallel sensing strips.

There may be less than four or more than four pairs of anti-parallelsensing strips per MBMS.

The MBMS may include a series of independent pairs anti-parallel sensingstrips in a row. Independent bending points can be monitored along theMBMS by the independent pairs of anti-parallel sensing trips whereaseach pair of anti-parallel sensing strips may sense (independent fromother pairs of anti-parallel sensing strips) a single bending point. Inthis manner, each bending point is detected and monitored by a differentset of coupled anti-parallel sensing trips. When the size of the pairsof anti-parallel sensing strips fits the different bones of a finger theMBMS may accurately monitor the movement of the finger.

FIG. 18 illustrates a ring shaped sensing element 780 according to anembodiment of the invention.

In FIG. 18 the gradient is a width gradient that changes along the ringin a radial manner. The pair of anti-parallel sensing strips includesarc shaped strips 781 and 782.

In this way, the mean position of a touch point along the archedanti-parallel sensing strips can be calculated as well as the touchlevel/force according to the measured resistance of the two strips.

FIG. 19 illustrates a printed hexanethiol capped NP 790 with widthgradient according to an embodiment of the invention.

FIG. 20 includes graph 800 that illustrates a sensitivity of a widthgradient sensor to constant speed strain (1.5 mm/sec) as a function ofthe location along the sensing strip according to an embodiment of theinvention.

FIG. 21 illustrates two layers 811 and 812 of a two dimensional array810 in which the gradient is a width gradient according to an embodimentof the invention.

FIG. 21 illustrates the pairs of the sensing strips as well as theconductors that are coupled to the sensing strips.

For example, see conductors 811(1) and 811(2) of first layer 811 thatare coupled to a pair of anti-parallel sensing strips 811(3) and 811(4)respectively.

For example, see conductors 812(1) and 812(2) of second layer 812 thatare coupled to a pair of anti-parallel sensing strips 812(3) and 812(4)respectively.

The pairs of anti-parallel sensing strips of the first layer areorthogonal to the pairs of anti-parallel sensing strips of the secondlayer.

According to various embodiment of the invention the pressure sensingdevice may be included in and/or coupled to and/or attached tocomputerized devices such as computers, robots and smart objects.

The pressure sensing device may provide an interfacing and/or sensingmeans for sensing touch, enabling the computerized device to “feel”their surroundings.

Touch sensation provided by the pressure sensing device may provide thecomputerized device direct information on the contact between thecomputerized device and whatever comes into contact with it, enablingalmost instant feedback on the nature of the contact (e.g. magnitude,location, dynamics, stiffness and even texture).

The pressure sensing device may be embedded in various elements such asbut not limited to tactile smart patches that will allow computerizeddevices to feel the interaction with their surroundings

Non-limiting example of fields of use and/or applications that maybenefit from the pressure sensing device include:

Force mapping strips/patches

Analog touch-screens or touch pads (that add the dimension of touchmagnitude)

Touch sensitive medical devices/tools (for example, first insertionneedle in laparotomy) that might help surgeons monitor the feel oftissues and organs.

Touch-sensitive robots

Prosthetic limbs with tactile feedback that retain the sense of touch toamputees.

Slipping threshold sensors for robotic (or prosthetic) clamps/hands thatenable the robot (or amputee) to identify the slipping threshold betweenthe clamping fingers and the object and adjust the force applied by theclamp on the object to be above the slipping threshold (and not under).

Smart sports gear (grasp/impact monitoring).

Physiotherapy and rehabilitation smart glove/patch (movement and graspmonitoring).

Large area strain monitoring for crack and structural deformationdetection in air and spacecraft.

Interactive objects that react to touch

Lighting controller/switch (e.g. wearable RGB LED strips that areindependently controlled by a smart strip, where one end is the red edgeof the spectrum and the other end is the blue/purple edge of thespectrum, and the intensity is controlled according to the magnitude ofthe applied users finger force).

Sampled sound controller (e.g. a type of musical instrument thatproduces variations of a sampled sound, were the x axis defines the toneon the sound, the y axis defines the music scale, and the magnitude ofthe applied users finger force defines the intensity of the sound).

Track pitch/speed controlled that changes the pitch/speed momentarily orconstantly, in a manner similar to the jog or the pitch adjuster on aCDJ device, respectively).

Wearable smartphone controller (embedded into a wearable garment or wornseparately) for controlling key features, such as, but not limited to,answering an incoming call, ending a call, increasing or decreasing thesmartphone output volume, skipping between tracks, scanning within atrack).

Intensity control and/or function selector for universal devices (e.g.TV, AC, Video, Stereo, etc) with any 2D or 3D geometry (e.g. linearstrip, ring, rectangle, cap etc).

Multirotor or multi-coper drone controller that enables the user tocontrol the direction of flight of the drone and the upward or downwardacceleration of the drone.

Signature pad that records the shape of the signature and the pressureapplied by the hand on the pad during the course of writing of thesignature.

Torque metering strip.

Pulse or hart beat monitoring patch.

In the foregoing specification, the invention has been described withreference to specific examples of embodiments of the invention. It will,however, be evident that various modifications and changes may be madetherein without departing from the broader spirit and scope of theinvention as set forth in the appended claims.

Moreover, the terms “front,” “back,” “top,” “bottom,” “over,” “under”and the like in the description and in the claims, if any, are used fordescriptive purposes and not necessarily for describing permanentrelative positions. It is understood that the terms so used areinterchangeable under appropriate circumstances such that theembodiments of the invention described herein are, for example, capableof operation in other orientations than those illustrated or otherwisedescribed herein.

The connections as discussed herein may be any type of connectionsuitable to transfer signals from or to the respective nodes, units ordevices, for example via intermediate devices. Accordingly, unlessimplied or stated otherwise, the connections may for example be directconnections or indirect connections. The connections may be illustratedor described in reference to being a single connection, a plurality ofconnections, unidirectional connections, or bidirectional connections.However, different embodiments may vary the implementation of theconnections. For example, separate unidirectional connections may beused rather than bidirectional connections and vice versa. Also,plurality of connections may be replaced with a single connection thattransfers multiple signals serially or in a time multiplexed manner.Likewise, single connections carrying multiple signals may be separatedout into various different connections carrying subsets of thesesignals. Therefore, many options exist for transferring signals.

Although specific conductivity types or polarity of potentials have beendescribed in the examples, it will be appreciated that conductivitytypes and polarities of potentials may be reversed.

Each signal described herein may be designed as positive or negativelogic. In the case of a negative logic signal, the signal is active lowwhere the logically true state corresponds to a logic level zero. In thecase of a positive logic signal, the signal is active high where thelogically true state corresponds to a logic level one. Note that any ofthe signals described herein may be designed as either negative orpositive logic signals. Therefore, in alternate embodiments, thosesignals described as positive logic signals may be implemented asnegative logic signals, and those signals described as negative logicsignals may be implemented as positive logic signals.

Furthermore, the terms “assert” or “set” and “negate” (or “deassert” or“clear”) are used herein when referring to the rendering of a signal,status bit, or similar apparatus into its logically true or logicallyfalse state, respectively. If the logically true state is a logic levelone, the logically false state is a logic level zero. And if thelogically true state is a logic level zero, the logically false state isa logic level one.

Those skilled in the art will recognize that the boundaries betweenlogic blocks are merely illustrative and that alternative embodimentsmay merge logic blocks or circuit elements or impose an alternatedecomposition of functionality upon various logic blocks or circuitelements. Thus, it is to be understood that the architectures depictedherein are merely exemplary, and that in fact many other architecturesmay be implemented which achieve the same functionality.

Any arrangement of components to achieve the same functionality iseffectively “associated” such that the desired functionality isachieved. Hence, any two components herein combined to achieve aparticular functionality may be seen as “associated with” each othersuch that the desired functionality is achieved, irrespective ofarchitectures or intermedial components Likewise, any two components soassociated can also be viewed as being “operably connected,” or“operably coupled,” to each other to achieve the desired functionality.

Furthermore, those skilled in the art will recognize that boundariesbetween the above described operations merely illustrative. The multipleoperations may be combined into a single operation, a single operationmay be distributed in additional operations and operations may beexecuted at least partially overlapping in time. Moreover, alternativeembodiments may include multiple instances of a particular operation,and the order of operations may be altered in various other embodiments.

Also for example, in one embodiment, the illustrated examples may beimplemented as circuitry located on a single integrated circuit orwithin a same device. Alternatively, the examples may be implemented asany number of separate integrated circuits or separate devicesinterconnected with each other in a suitable manner.

However, other modifications, variations and alternatives are alsopossible. The specifications and drawings are, accordingly, to beregarded in an illustrative rather than in a restrictive sense.

In the claims, any reference signs placed between parentheses shall notbe construed as limiting the claim. The word ‘comprising’ does notexclude the presence of other elements or steps then those listed in aclaim. Furthermore, the terms “a” or “an,” as used herein, are definedas one or more than one. Also, the use of introductory phrases such as“at least one” and “one or more” in the claims should not be construedto imply that the introduction of another claim element by theindefinite articles “a” or “an” limits any particular claim containingsuch introduced claim element to inventions containing only one suchelement, even when the same claim includes the introductory phrases “oneor more” or “at least one” and indefinite articles such as “a” or “an.”The same holds true for the use of definite articles. Unless statedotherwise, terms such as “first” and “second” are used to arbitrarilydistinguish between the elements such terms describe. Thus, these termsare not necessarily intended to indicate temporal or otherprioritization of such elements. The mere fact that certain measures arerecited in mutually different claims does not indicate that acombination of these measures cannot be used to advantage.

While certain features of the invention have been illustrated anddescribed herein, many modifications, substitutions, changes, andequivalents will now occur to those of ordinary skill in the art. It is,therefore, to be understood that the appended claims are intended tocover all such modifications and changes as fall within the true spiritof the invention.

1. A pressure sensing device, comprising: a first and second sensingelements that comprise one or more piezoresistive materials; wherein thefirst sensing element has a first gradient; wherein the second sensingelement has a second gradient; wherein the second gradient differs fromthe first gradient; wherein a sensing circuit that is coupled to thefirst and second sensing elements, is arranged to sense at least one outof resistance and conductance of the first and second sensing elementsand to determine at least one out of a location and a load of an eventthat involves applying pressure on the first and second sensingelements.
 2. The pressure sensing device according to claim 1 whereinthe one or more piezoresistive materials are selected from a groupconsisting of electrically conductive nanoparticles, nanotubes,nanowires, carbon nanotubes, carbon nanowires, and a combinationthereof. 3-6. (canceled)
 7. The pressure sensing device according toclaim 1 wherein at least one of the first and second gradients isselected from a group consisting of a thickness gradient width gradient,concentration gradient, a resistance gradient, sensitivity to straingradient, capping layer thickness gradient, and a combination thereof.8-12. (canceled)
 13. The pressure sensing device according to claim 1,wherein the first and second gradients facilitate a determination of aload of and a location of an event that involves applying pressure onthe first and second sensing elements.
 14. The pressure sensing deviceaccording to claim 1 wherein the first sensing element comprisesmultiple first regions, wherein the multiple first regions differ fromeach other by location; wherein at an absence of the event there is aone to one mapping between a given property of a first region and alocation of the first region.
 15. The pressure sensing device accordingto claim 1 wherein the second sensing element comprises multiple secondregions, wherein the multiple second regions differ from each other bylocation; wherein at an absence of the event there is a one to onemapping between a give property of a second region and a location of thesecond region.
 16. The pressure sensing device according to claim 15wherein the one to one mapping between the given property of the firstregion and the location of the first region is anti-symmetric to the oneto one mapping between the given property of the second region and thelocation of the second region.
 17. The pressure sensing device accordingto claim 1 wherein the first gradient is anti-symmetric to the secondgradient.
 18. The pressure sensing device according to claim 1 whereinthe sensing circuit is arranged to determine the location at a spatialresolution that is a fraction of length of the first sensing element.19. The pressure sensing device according to claim 1 wherein the sensingcircuit is arranged to determine the location at a spatial resolutionthat is less than one percent of the length of the first sensingelement.
 20. A pressure sensing device, comprising: a sensing elementarray that comprises multiple sensing elements that comprise one or morepiezoresistive materials; wherein the sensing element array ischaracterized by a sensing array given property function that mapsvalues of a given property of the multiple sensing elements to at leastone out of location and a load of an event that involves applyingpressure on at least one sensing elements of the sensing element array;wherein the location of the event is selected out of a group oflocations that are associated with the sensing element array; andwherein each one of the multiple sensing elements is associated with aplurality of location of the group of locations. 21-22. (canceled) 23.The pressure sensing device according to claim 20 wherein the one ormore piezoresistive materials are selected from a group consisting ofelectrically conductive nanoparticles, nanotubes, nanowires, carbonnanotubes, carbon nanowires, and a combination thereof. 24-27.(canceled)
 28. The pressure sensing device according to claim 20comprising a sensing circuit that is coupled to the sensing elementarray, is arranged to sense resistances of at least some of the multiplesensing elements of the array and to determine the location and the loadof the event.
 29. The pressure sensing device according to claim 20wherein at least two of the sensing elements of the sensing elementarray differ from each other by their sensing element given propertyfunction.
 30. The pressure sensing device according to claim 20 whereinthe at least two of the sensing elements of the sensing element arrayhave sensing element given property functions that are anti-symmetricalto each other.
 31. The pressure sensing device according to claim 28wherein a pair of pressure sensing elements is characterized by a givenproperty function that is injunctive and maps values of the givenproperty of the sensing elements of the pair to at least one out of alocation and a load of a deformation event applied on at least one ofthe sensing elements of the pair.
 32. The pressure sensing deviceaccording to claim 31 wherein the sensing elements of the pair havesensing element given property functions that are anti-symmetrical toeach other.
 33. The pressure sensing device according to claim 20wherein the array of sensing element is a strip that comprises twosensing elements that are substantially parallel to each other.
 34. Thepressure sensing device according to claim 20 wherein sensing elementarray comprises first and second layers of sensing elements; wherein thefirst layer of sensing elements is positioned above the second layer ofsensing elements.
 35. The pressure sensing device according to claim 34wherein the first and second layers of sensing elements aresubstantially parallel to each other or substantially normal to eachother or oriented in relation to each other. 36-37. (canceled)
 38. Thepressure sensing device according to claim 34 comprising an intermediateisolating layer that is positioned between the first and second layers.39. The pressure sensing device according to claim 34 comprising atleast one intermediate layer that is positioned between the first andsecond layers.
 40. The pressure sensing device according to claim 34comprising at least one protective layer that is coupled to an exteriorfacet of at least one of the first and second layers.
 41. The pressuresensing device according to claim 20 wherein each one of the multiplesensing elements is associated with at least one hundred location of thegroup of locations.
 42. The pressure sensing device according to claim20 wherein the sensing circuit is coupled to the sensing element arrayby a set of conductors, wherein a number of conductors is in an order ofa number of the multiple sensing elements.
 43. (canceled)
 44. Thepressure sensing device according to claim 20 wherein a sensing elementof the multiple sensing elements has a spatial character thatmonotonically changes along a longitudinal axis of the sensing element.45. The pressure sensing device according to claim 44 wherein thespatial character is a width of the sensing element or a height of thesensing element.
 46. (canceled)
 47. The pressure sensing deviceaccording to claim 20 wherein a sensing element of the multiple sensingelements has an electrically conductive nanoparticles concentrationcharacter that changes along an axis of the sensing element and/ormonotonically changes along a longitudinal axis of the sensing element.48. (canceled)
 49. The pressure sensing device according to claim 20wherein a sensing element of the multiple sensing elements has aresistance that monotonically changes along a longitudinal axis of thesensing element when the sensing element is not under pressure.
 50. Thepressure sensing device according to claim 20 wherein each sensingelement is a strip.
 51. A pressure sensing device, comprising multiplepairs of sensing elements that are arranged in a serial manner to coverdifferent regions of the sensing device; wherein each pair of sensingelements comprises a first and second sensing elements that comprise oneor more piezoresistive materials; wherein the first sensing element hasa first gradient; wherein the second sensing element has a secondgradient; wherein the second gradient differs from the first gradient;wherein the first and second thickness gradients facilitate adetermination of a load of and a location of an event that involvesapplying pressure on the first and second sensing elements. 52-59.(canceled)